1. Field of the Invention
The present invention relates to apparatus for securing cargo and, more particularly, but not by way of limitation, to a tie-down apparatus for securing drum-like containers in place against movement on a cargo vehicle, floor or platform.
2. History of the Prior Art
Steel drums, kegs and the like are and have been used extensively in industry for containing, storing, shipping and dispensing products. The drum is relatively easy to manufacture and exhibits high strength characteristics due to its shape. Drums come in a variety of sizes varying in both height and diameter, for the purpose of containing articles of manufacture, bulk goods, liquid and gas.
However, since the first drum was shipped on a cargo vehicle, there have been problems securing the drum in place against movement relative to the vehicle. The same shape that makes the drum strong and easy to manufacture also makes it difficult to tie down.
Naturally, the drums could be fitted into rectangular containers for ease in shipment, as are canned goods; but this would require the effort and expense of building secondary containers.
A drum is a difficult container to secure under high horizontal longitudinal or lateral loads because it has few features for grasping the drum without subjecting the side wall, the weakest surface of the drum, to loading which is apt to damage the drum.
One attempted solution to the problem of tying down drums and general cargo is presented in the patent to Klasing, Jr., U.S. Pat. No. 3,154,026, issued Oct. 27, 1964 for an "Articulated Tie-down Load Control Bracket".
The Klasing, Jr., device consists of inverted L-shaped brackets which fit over the upper rim of the drum with downwardly extending leg members which rest on the drum wall. The upper portion of the L-shaped brackets are attached together by chain links across the top of the drum and the lower leg members of the brackets are secured to tie-down points in a manner to prevent vertical or sidewise movement of the drums.
However, if the drum secured by the Klasing, Jr., device experiences rapid acceleration in a horizontal longitudinal direction, in line with the brackets, the downwardly extending leg members along with the tie-down chains would tend to dig into the drum sidewall, which, as stated, is the weakest part of the drum.
Other methods of securing drums in place in cargo vehicles include the use of webbing or straps which extend around the drum body and are typically attached to tie-down points on the walls of the cargo vehicle or the like. This method usually takes up a considerable amount of cargo space and requires the abilities of a skilled load master in order to assure that each drum is properly secured.